Problem: What is the greatest common factor of $6$ and $10$ ? Another way to say this is: $\operatorname{gcf}(6, 10) = {?}$
Explanation: The greatest common factor is the largest number that is a factor of both $6$ and $10$ The factors of $6$ are $1$ $2$ $3$ , and $6$ The factors of $10$ are $1$ $2$ $5$ , and $10$ Thus, the greatest common factor of $6$ and $10$ is $2$. $\operatorname{gcf}(6, 10) = 2$